SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '28a59ed5abb535cc9d1131148eed4844efae476bec89b1dc4b16949ebdc3612a' 
  AND token = 'gam55vBumhoNZGSo9R0UctK0nz5b9DRQUjD8IlAzi4k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00112

JSON explain

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