SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '85dd17889fcc14374a0db885c3effb18fb2b55ab195336f70dbd6739e71ca3aa' 
  AND token = 'QEHNIM6E1V++6PH7ra6plANFW7wARnOgn28b4NmjcXE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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