SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6e361df985df563223ee67131a4e7f4697554dbd564380a47757e45a29e8cdab' 
  AND token = '0dKGuwEvWEpAbrKlM9YAbqWJhXnSD9bqWxqeAZyL3zU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00070

JSON explain

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