SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2828a2d73fe182dba9d51efbeb6699dede874a06383e023afab8075c4fb58f12' 
  AND token = 'DRMjUy7kiZhB/DYXQI4KYRyGn4NbgnQsxiVCtXkq/q0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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