SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bca789597fa9a962dac8b3965d76edb57849345a21889d9eb1fe91c04fd7371a' 
  AND token = 'xqj5QO1vG5M3HzeXqTKmLus8ImZBP2WCfBa4zUR7rTY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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