SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7ff4c9cba24cefbdb4165ec0a46572912076681dbb8b4bb7bc46efeac281365a' 
  AND token = 'zCDwTAxaCi9ByPCm2+a+YUG/D3GhJvsvK9NpAVqsxOg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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