SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '41c65a4b4719edf1d2d7ac9514204c13a4c3285ebe62b0e8086906c3c1b2b8ab' 
  AND token = 'a4+zOaXCueD/XWnZ54csqPBKoDNySIVniE3WYwqlObE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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