SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e2a9fd4d6a456b685a654b69911a91104c0c90a3282186d2690e5ca0892a1e34' 
  AND token = 'x/qFOjN/yTJ3BESCgYY8tZm6j+RXPcHWPRlwyY7eC9E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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