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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '923c0dd9192d4a9bd15b5014f23eb75a79a2e5a9e33379572fc023d55bdbcb1b' 
  AND token = 'B4o0sSdt7uJDJ/C4giV+zoQXaPMn95JLqfCCQP3jYqA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}