SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '998b1b580f0ef2a32f3ab384d078186c89d895ed2eace779e199b034d4be548f' 
  AND token = 'aeKb9xUol3Nq8P3/kq4IhUncggc298C2uzxbqkt0Dy8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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