SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '21a190105ec79685e06c1bf3e4fb85aa380b541fc97334f64acf1abe29c97c78' 
  AND token = '99yuhbvoTpjdgki7xIImYSFiDFFJNT9izeSRb8YkGW8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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