SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd3b7629c842a4b762ffce1bb67e22e8ece58027a500d6258b7ae4300e497d449' 
  AND token = 'zhaKEmUWlhZkn4PFBidoN6wiItIV5thszbaAJiVIrO0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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