SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8409420faa9652f8583c547215b922b2db135e6dfbf80151382580e3df29ee0f' 
  AND token = 'cwiz5n0rxq+ffCCmU/t9ZFPWdSpnuNUnlU7sByEnT9I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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