SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '447594388f3c410f04821dab20898d15d966b86fa5df10607fb212334dfdec22' 
  AND token = 'ecOVhXOJMRTltraAFoEuXpF5237dojZCbhGW2MXOE84=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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