SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ee26bd7988a58856b856a4d8437c14bacd8eee827bdba78783b781ff556b5141' 
  AND token = '3DkGAdmu1JfOxYRcHL24jRvecirDmoakGwNELDoWx+U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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