SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cd8b6682dda124052628f8deb35cb5d458b99f8d0162c6ffd9c1decafa14f29f' 
  AND token = 'QEyttfcdlz/awu46bDXMDPHYk95saoMtlIqdXAuRo6g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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