SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8811742e6737692108f1683ffa6c799a0585c9310066234e2624801dffd842d2' 
  AND token = '/JTgwXjjfpom+flVOn08YGtGyFKNPYM/oM3kPPdvJW8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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