SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bfe9e04df6b8cc456a6cb0249255680569a2ca0866e75fd64a9d753ccf161a2d' 
  AND token = 'p+T89LV+3FZQU5nhiIwl3QNuIFkC2vQ27GU37GmBJPY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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