SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '12b6747611e95f8ed43ab91cbb1bb38e535aadc522cbacea57ec005c59ca9634' 
  AND token = 'ruRknpqz4/v/yy0qkXDS/0O6IhRHmceDOb/89FPzBig=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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