SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a33a84f2cf67af75f18c1f9983a961b1a5443e481656d0d8d7e705a9260ef2bd' 
  AND token = '2QCIUjDlr0+z8jLI+/GGwMeF6SDwCjTZL2oWUs09EV4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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