SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd7cfea8a284b71a2521ae5cd702d732412cfcdc679054d6d5dc005c4a40fb0cb' 
  AND token = '9qWpzvx/V/K3mrlVvcfDtxOxPuBRmxyheM9MSWIoUto=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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