SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f6ecfcb616faf98b27e2bdf0f0a39ed50d667f838ab80ac69c153bdc2995a593' 
  AND token = 'l1r6YmykQFHu8ksrFbN+1/SdQ7U4r9Hgh7cIKIrXHjU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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