SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4806adda42a4736cb9e89e7e65aadf886460762e97ce865d9f7393f34861c3d7' 
  AND token = 'S/Phy67tt2flqVs4fbJgo+wOLzULYxBx/lyInQuDwMs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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