SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '41bd31ebe6d9dc603dc09f9874956549a668ed218286cdbfbda75cb7f5002743' 
  AND token = 'g9nVbCFHaluw27FK8dPujt2k+kELaRArQ5pqedu18/8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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