SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '32149dae64371879f741c7880f28841f0f935686196a28cf8a2938668633d5d5' 
  AND token = 'fVst3Q5qUmIZ96TWGCrIbqz/okxYHEl6XdajotWFu40=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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