SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e034063aa3602ae5478d71f8797019c1d2b9ed41bc71881aca13c782c88b55ca' 
  AND token = 'ZQwq8W8ZfLC4ZdWP5QL+zVS/vAzyC/81EqpBJJgEmsA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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