SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7666ddfc5a19ccec73b25dbd6ba12f88e0cd76245b1eff04b76456ea0d43c723' 
  AND token = '9uO2dVlOLI/NVr2jYnNZWaAF2qcqTJIp8SHPzhF0+i0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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