SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd04e93d222cd09e37aa82dcf6251691aac0d7bbdf0499f2df924bc4ccb219e7c' 
  AND token = 'Rf5F5ej7QDHW1LQJoznyL4J/YHOweTISMBaUFeqpmEg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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