SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'af41baf6d91997a1c8466cc2b0090f9bf3fbbac73ad908e5ddbfe62319cc4f01' 
  AND token = 'HdIhPwytCCku8mHYdRcJL27FOeW+v3vbHRDTbojonbE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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