SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bda19a35592c5e33bb850c0d9892f3942da07b40a18d1900ad1655659c770d26' 
  AND token = 'iU2qOQ3G8jQYqvPIK2ulLL8ghz7zB2tBfkkVrbgI+VM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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