SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a86d95e4bf2ec3848cc853ee472aeeb6681297adb21ed337331c251938ed2d47' 
  AND token = 'zD6Vrq7Q8NKAoMiJM69UzUqpRX+EPiaEAJ4sQhSnCVM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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