SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '00d6ad0a587e697ee7b66f385ee96257da9929568df783cb8e60440b121707a8' 
  AND token = 'WZW7c0XoVYj2rj2Nh+RM7vC4G+GM4tBZZlwFzMYz+B0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}