SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '43283560e327dca4379d18033d171645c92844022682f137b7ca05bf0111b466' 
  AND token = 'Dv3FdzlQMYqHkrsObdRqv3AIwOmRz6iMwhaUp7ZPP0s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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