SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e7cf0b207da0fd23d73047fe12882809872300d3b22a32d245c03705447993b0' 
  AND token = '/WLx382y2lqqP3kCrTdGPkLWjBgOtG2RnIbM5c5zPuM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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