SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '47cd06af656f230c10fa1f2bb3df0db353d4835103fff8a537f6a86fb53407c4' 
  AND token = 'm+Fy0yvPKMK92SZZKhNCjPTmBbd4OYqEkab2QUmMlDc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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