SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fb8393586c223aef06067e6e9c097c769fde638ef0a3c8dd054ab2bc6a095689' 
  AND token = 'WNA8Qn8JPq5zsLlU5sIeBlqTSNxa6GiimgbBsc09THM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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