SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ce9317b07e7f331d758d9e6a4b213a26a9d36e8d109bcbe3b498a11f7ad4a781' 
  AND token = 'RAk9hiICZ5gZqJE1VtpLNiDB4Y+Cz+mCBOJt8bpwPvs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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