SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '37b1820b03f43b221898131d7deb2164c04644b886dd862897be561d30704abd' 
  AND token = 'TfAdANWlyaB/T/DGvoPq3GVhHwld8YbY2BdpnX/DLPI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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