SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7175f43eb81800d547f8a96677182a4231d81d7379c8f4fa627543ffa262de81' 
  AND token = 'IudEq4RlGxpm/7/vCZxYYDAwBLhVJuonwQ9Xvq7QEAI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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