SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'ed43173ed968a19a3fdcebb1247e80eb0d9a37df5a3ed30de4653257c7b1fc7e' 
  AND token = 'xKrJEvkN2ueiyCHfQK0JNZxzJE4GTYAw3Z8tXY5p1kQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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