SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '213457a07f9f6e1fd8f4726966047c2da888503abaee4aee13f705059d9be34a' 
  AND token = 'rinROqhjW8T3P+tnk9DLsJR/liPwuGmi6SEXacTZg+s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00053

JSON explain

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