SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4fe7b1823ddcc9510b85a14167141e9c3806f0386a425b5ce9a5f328ebbd4006' 
  AND token = 'LKMqko5ZvdDeitozjURLdMGHguhCJfSPD4/t576W5ao=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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