SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ce54d0c4abb3c384b9153991eeeb30a0990a318f8fed174288183641b8914bed' 
  AND token = '6uNuOSpQ0wFZzyjFUG7pxbCwhHTux4MMPiiYTL5glFk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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