SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8f955b040e6ef43a04029674a3f70cc2ff377aa34cd4efda3601ccc2011f4e38' 
  AND token = 'uuMEl5GPlJeIjKeWd+XWQvE+HIfd3Z4VEDPjZIdQ+uA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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