SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4033a1cb9411295e723ead831cdcba395930eb65993c3bcc544fb1485a6f47eb' 
  AND token = '2QbExdjv4mfXhNM6VzqlLTYVZAg6S30C6aJeuYUT4G4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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