SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6deb4275c9bab46aa8bed1168ff33ae9eb7fc80799dbf3f823c7e8819ec64bae' 
  AND token = 'gSlFYrs9277tJ1ufTCITd539llaA7Ws29XlyYTwZQfk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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