SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a5d84fcc27906e1563d6b8271a04c62428d5468f0079ae152f9b13c79829ff5f' 
  AND token = 'M9R/VywfSze+Lh4glKQyBfrAZ6aZcnn4cdhFgMeRgMw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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