SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '484ad3a75d1a629253e5d60be5df126ddf026a5d6952d1a30283b0ae87eb4b8e' 
  AND token = 'XyOncITi6AyJhjds4Tm6E6/yFv+27OTeIFUE4OM/GQ8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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