SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'facd101d8324661ce30f58cdb0ab9301cb7f2d0b7d7111fb819382917ee4e10a' 
  AND token = 'gPKCv2jcwXhb0+creFU9fBK/0gS8sKiBJ+IaYVCZgAA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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