SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '71be1ef6fdb5a85710fc408994edba6e8b52db9a45dc5ab42d2ecd87b06feeeb' 
  AND token = 'frpJVGoBX/YF4a9gdh4bdOUAx4B8NbGJgS+BMBVVCyo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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