SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ecaf1ee0af9a8064dddc05b71cc09eb15f2614298ad6e0bcdeb2002f12e30173' 
  AND token = 'YDB72dBDRYJXRAm6Uvx6/Sa8AjpzzDJAYrzBS71e7X0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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