SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '581a480a793ed89af059c1b670bed0973892befeb111ffc76f5ed20e8c6938d7' 
  AND token = 'QS+TS8ticyNVgy81C8+IRnnvMdXplK/XtSWioJ5zVkg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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