SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '0c40ef6df797a84e89252cc6415977206cbe632515639ad1528ce2d81a84ecb3' 
  AND token = 'Jf/cRzKhKvT7g8YSVk6bwa2Cl83QBMt/cKuCS0KkfEk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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