SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd8986c9176fe9fa85c1d2350965dba79105cd17d344cdc09431484e5d779cd9e' 
  AND token = 'Hec0njj2HsnvVkCjaEiDoDTmEOYZ2GXUnEMOlHsp6OA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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