SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd37edb03878ceb11f959ffdbe67b24d4d3951bc899920ed3748d08e9859d011a' 
  AND token = 'WMU4eLChrNchspQffIjQ8MtY59EFxbP4D8BuqHhNbW4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00054

JSON explain

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