SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '914b412a4777bcffb5269f2a53f6e4ce87a9d3f1f2ecac39042f27688dd778fa' 
  AND token = 'Kf+pSahusOMfAJlq9TIuyMJC75jolqHl+mOELF/eYEU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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