SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dd4e3092c032a847f19811e81159ad1b8a7499b26073c3f5bf72ebcf13f2899d' 
  AND token = 'nyyQFomw09APIDjzRbvB5CtdJBzPyhYnWRJmLRKyBq4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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