SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '440135319b072d230e9d21818ffda267ec7f2abf3b2943cffe05aae4e2d7924c' 
  AND token = 'Qp+1CpY5+UOoWbAFUhVaDHuiKJ6j4ILGGT/4D5o2HDw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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