SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eec2fb84e0d7be89c5a81f26ae58624a667f932f0a622938918666096326020d' 
  AND token = 'lFioIp7sLw/wtmnzlglS13zyxcrtIu8Y/q7gFAiVAAc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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