SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '81a1b091ee8a983b1171865e354a1f6b3bd840c021d08af1ab9202eb4b27e384' 
  AND token = 'iIEq59sHpvpWA1XqKg/YPP/45GUstClJxp/PgzFRxVY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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