SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd61275981a6b9a2b15796ac85f809b09b67396f571e2380514669b1527ff25b9' 
  AND token = 'zIAGhcwxbjGNh6Q4bn78UVNP/Q7eSi9sIUBzTtH7jjs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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