SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4d2cc83b072f78fb93d4240219642cc39d109d1b53d81ff15ea310619e8df33b' 
  AND token = 'O26hcO1uLtFrpRce8Rm8jWps6Vau7BAYfDBUP9FzBpE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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