SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c8566743f4f2c4dbd58e3e9388b3149e86c6d7c9824e002e2ce35b2504898311' 
  AND token = 'ddbeW/z3o6EEsAy7kAbBAo+moSXkc+KI+HRcrT0JMX8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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