SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '569571d38a5610e185eab9cc8f16e71497b48b224b383d806e082534c60a1859' 
  AND token = 'xhoetmjzvZnG8CysJ9GFUwFQJFFIZ37PN8Qfm7cOY6k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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