SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '63f7e3ef208d24fc634e238c84b63a48860b70d45ab8ca5ae86041802621d8dd' 
  AND token = 'Ip61FjIHSWoQwBCR+MF4siWBmPp7fkZper5YuD4ppsQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}