SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '153cf3fee679918cbb5628acd151bab3e7e09b71b93ccda47917afdb67bde6c6' 
  AND token = '9WbRIDZTVZMCyrKa80kp222iFMKozDxRt+CchpIGqSM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00098

JSON explain

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