SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4549522ee3eb1a34697c6fae92a84a51269ae303db925dc98bf0652893ee0055' 
  AND token = '7DUxPWQd9+9ybGqgvs3u/SqEfCgOlB+oOWifuf8yaS0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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