Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3985a82eb63ab5a995c43909388b0ab67ef2fb60eece95621b2859e63ca35139' 
  AND token = 'FwtuiPdW2JVnrPzTnvTMon//lAnExndRQcZNALt3As8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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