SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'debfc338508ff69576a735127375b9d5ba40bb3b0183a8530723ce2c0ecd7fb7' 
  AND token = 'JRuS+/adCF8vYSH30H7r2WVnrwTIqex/Yex8GuWZHqU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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