SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1bb7f8b24dccf797b8d03f6f017ccfefc6fd093576c2c9274243291da1234250' 
  AND token = 'JZXS2CYW2ZgCIBVq4TQvDQYzY+IHtQZECf2SGs+RnHw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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